Merge pull request #10231 from mwielgus/cassandra

Fix IP field name and add namespace support in Cassandra example

examples/cassandra/README.md

@@ -45,6 +45,10 @@ spec:
       value: 512M
     - name: HEAP_NEWSIZE
       value: 100M
+    - name: POD_NAMESPACE
+      valueFrom:
+        fieldRef:
+          fieldPath: metadata.namespace
   volumes:
     - name: data
       emptyDir: {}
@@ -52,7 +56,7 @@ spec:
 
 There are a few things to note in this description.  First is that we are running the ```kubernetes/cassandra``` image.  This is a standard Cassandra installation on top of Debian.  However it also adds a custom [```SeedProvider```](https://svn.apache.org/repos/asf/cassandra/trunk/src/java/org/apache/cassandra/locator/SeedProvider.java) to Cassandra.  In Cassandra, a ```SeedProvider``` bootstraps the gossip protocol that Cassandra uses to find other nodes.  The ```KubernetesSeedProvider``` discovers the Kubernetes API Server using the built in Kubernetes discovery service, and then uses the Kubernetes API to find new nodes (more on this later)
 
-You may also note that we are setting some Cassandra parameters (```MAX_HEAP_SIZE``` and ```HEAP_NEWSIZE```).  We also tell Kubernetes that the container exposes both the ```CQL``` and ```Thrift``` API ports.  Finally, we tell the cluster manager that we need 0.5 cpu (0.5 core).
+You may also note that we are setting some Cassandra parameters (```MAX_HEAP_SIZE``` and ```HEAP_NEWSIZE```) and adding information about the [namespace](https://github.com/GoogleCloudPlatform/kubernetes/blob/master/docs/namespaces.md).  We also tell Kubernetes that the container exposes both the ```CQL``` and ```Thrift``` API ports.  Finally, we tell the cluster manager that we need 0.5 cpu (0.5 core).
 
 In theory could create a single Cassandra pod right now but since `KubernetesSeedProvider` needs to learn what nodes are in the Cassandra deployment we need to create a service first.
 
@@ -158,6 +162,10 @@ spec:
               value: 512M
             - name: HEAP_NEWSIZE
               value: 100M
+            - name: POD_NAMESPACE
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.namespace
           image: gcr.io/google_containers/cassandra:v4
           name: cassandra
           ports:

examples/cassandra/cassandra-controller.yaml

@@ -24,6 +24,10 @@ spec:
               value: 512M
             - name: HEAP_NEWSIZE
               value: 100M
+            - name: POD_NAMESPACE
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.namespace
           image: gcr.io/google_containers/cassandra:v4
           name: cassandra
           ports:

examples/cassandra/cassandra.yaml

@@ -26,6 +26,10 @@ spec:
       value: 512M
     - name: HEAP_NEWSIZE
       value: 100M
+    - name: POD_NAMESPACE
+      valueFrom:
+        fieldRef:
+          fieldPath: metadata.namespace
   volumes:
     - name: data
       emptyDir: {}

examples/cassandra/java/src/io/k8s/cassandra/KubernetesSeedProvider.java

@@ -35,7 +35,7 @@ public class KubernetesSeedProvider implements SeedProvider {
     
     @JsonIgnoreProperties(ignoreUnknown = true)
     static class Address {
-        public String IP;
+        public String ip;
     }
 
     @JsonIgnoreProperties(ignoreUnknown = true)
@@ -102,7 +102,8 @@ public class KubernetesSeedProvider implements SeedProvider {
         List<InetAddress> list = new ArrayList<InetAddress>();
         String host = "https://kubernetes.default.cluster.local";
         String serviceName = getEnvOrDefault("CASSANDRA_SERVICE", "cassandra");
-        String path = "/api/v1/namespaces/default/endpoints/";
+        String podNamespace = getEnvOrDefault("POD_NAMESPACE", "default");
+        String path = String.format("/api/v1/namespaces/%s/endpoints/", podNamespace);
         try {
             String token = getServiceAccountToken();
 
@@ -110,6 +111,7 @@ public class KubernetesSeedProvider implements SeedProvider {
             ctx.init(null, trustAll, new SecureRandom());
 
             URL url = new URL(host + path + serviceName);
+            logger.info("Getting endpoints from " + url);
             HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
 
             // TODO: Remove this once the CA cert is propogated everywhere, and replace
@@ -125,11 +127,14 @@ public class KubernetesSeedProvider implements SeedProvider {
                 if (endpoints.subsets != null && !endpoints.subsets.isEmpty()){
                     for (Subset subset : endpoints.subsets) {
                         for (Address address : subset.addresses) {
-                            list.add(InetAddress.getByName(address.IP));
+                            list.add(InetAddress.getByName(address.ip));
                         }
                     }
                 }
-            }
+		logger.info("Available endpoints: " + list);
+            } else {
+		logger.warn("Endpoints are not available");
+	    }
         } catch (IOException | NoSuchAlgorithmException | KeyManagementException ex) {
 	    logger.warn("Request to kubernetes apiserver failed", ex); 
         }